should be increased in weight by about 50 percent. A model design wave 

 height of 16 feet was selected for the test structure, which corresponded 

 to a value of 14.9 for K in equation (6-4b) . The results of the wave 

 transmission tests are shown in Figure 6-21. The figure also shows that 

 the transmission coefficient, H^/H^^, varies with the wave period, in- 

 creasing as the wave period increases. The maximum transmitted wave 

 height of 3 feet for the selected prototype design wave height, based 

 on the prototype wave climate of 13 feet, was considered satisfactory 

 for the type of ships that would use the harbor. The stability tests 

 of the breakwater section using uniformly placed limestone blocks (Fig. 

 6-19) showed that the largest waves tested (18 feet in height) did not 

 remove any of the armor units from the structure; however, damage to the 

 W/2 stone section began at the 11-foot height, and several of the W/3 

 stones on the harborside were displaced by 12-foot waves. Also, because 

 of the smooth surface and lack of voids in the armor-unit section, the 

 runup and overtopping increased and the waves generated on the harborside 

 increased to about 4.5 feet for the 13- foot prototype design wave. Thus, 

 for these reasons, and because it was not considered practical in the 

 prototype to place the armor units below the water level in the same 

 manner as in the model, this plan was not considered suitable for use 

 in constructing the full-scale structure. After testing several break- 

 water sections with limestone armor units randomly placed, it was decided 

 that the section shown in Figure 6-20, in which randomly placed limestone 

 blocks were used, would be satisfactory at Bums Harbor. This structure 

 was considered stable for waves as high as 18 feet when tested with a 

 Stillwater level of +4 feet LWD. This corresponds to a value of K of 

 14.0 in equation (6-4b) , using an assumed effective value of Wg^ of 13 

 tons. When tested using a Stillwater level of 0.0 foot LWD, the struc- 

 ture was stable for a maximum wave of 15 feet in height, which corresponds 

 to a K of 8. 1. The rather high values of K for the tribars and the 

 limestone armor units were caused by the large amounts of overtopping for 

 the high Stillwater level and the larger wave heights tested. The trans- 

 mitted wave heights for the most stable section tested (Fig. 6-20) are 

 shown in Figure 6-22 for both the +4 and the +0.0 Stillwater levels. The 

 transmitted wave heights corresponding to the 13-foot prototype design 

 wave were 3 and 2 feet for Stillwater levels of +4.0 and 0.0 feet, 

 respectively. 



(b) Example of a Minimum Study . 



1 Project . Proposed expansion of Monterey Harbor, 

 Monterey, California. 



2_ References . Davidson (1969) and Chatham (1968). 



3^ Laboratory . WES. 



4_ Test Period . September 1969. 



5 Problem . Monterey Harbor is located at the southern 

 end of Monterey Bay about 100 miles south of San Francisco, and is exposed 



378 



